When in multiple selection mode, typing works very well - kudos on making such an
unusual feature work well. However, I often make typos, and enjoy using the backspace
key to delete - which doesn't yet have perfect support in multiple selection mode.
It stores each backspace as a separate state in the undo history (fine), but also
does not impact the first range selected. This makes multiple selection overwriting
by typing less useful than it could be.